A layer-2/layer-3 (L2/L3) network switch routes data packets between other network devices connected with the switch, such as other switches and servers that host virtual machines. From time-to-time, the network switch is upgraded with a new operating system and other new configuration items, for example. Also, the network switch may need to perform a reboot or reset (referred to more generally as a “reload”). Typically, such an upgrade or reload may take an extended period of 5 to 10 minutes, during which time the network switch is unable to route packets. As a result, the network switch may lose connectivity with the other switches and the servers. The lost connectivity may cause existing communication links to be “torn-down” and the virtual machines to “crash.” In large networks that employ thousands of network switches, problems associated with this extended period of lost connectivity causes large-scale network disruption, which frustrates network operators and users alike.